An oscilloscope has typically several input channels that can be used for analyzing appropriate signals inputted. For the analyzing, the oscilloscope has an internal signal analyzing circuit that receives the appropriate signals to be analyzed. There are signal analyzers for a long time which are able to acquire an input signal at a first channel, to acquire another input signal at a second channel and to analyze the input signals simultaneously in an oscilloscope-like manner in the time domain and in a spectrum analyzer-like manner in the frequency domain, respectively. In addition, known signal analyzers are able to acquire the first input signal and analyze the same in time and frequency domain. Spectrum analyzer-like manner means to down-convert the frequency of the input signal.
In contrast, other signal analyzers are known to offer time and direct FFT-like frequency domain analysis wherein FFT is an abbreviation for Fast Fourier Transform. FFT-like frequency domain analysis means processing a digitized input signal according to a FFT algorithm to generate frequency data without any frequency down-conversion. This is also called a simple FFT mode.
However, the simple FFT mode has a limited bandwidth as well as a limited resolution compared to down-converting the input signal as it is done in the spectrum analyzer-like manner.
Nowadays, modern multi-domain oscilloscopes make use of these longstanding concepts. They process signals both in the time domain and in the frequency domain. Accordingly, it is possible to provide information to a user regarding a time domain and a frequency domain. Other modern oscilloscopes have a built-in dedicated spectrum analyzer.
In the state of the art, oscilloscopes are known that have dedicated channels with regard to the analyzing purposes. Such conventional oscilloscopes comprise two or four time so called time-domain channels and one frequency-domain channel. This means that the time-domain channels are configured to only perform a time domain analysis whereas the frequency-domain channel is configured to only perform a frequency domain analysis. However, this limits the capability or rather the flexibility of the oscilloscope.
Moreover, oscilloscopes are known that perform the time domain analysis and the frequency domain analysis for each channel simultaneously wherein the analyzing results are stored in a subsequent acquisition memory. However, this results in an oscilloscope requiring a lot of storage capacity of the acquisition memory since both the frequency domain analysis results and the time domain analysis results are stored appropriately.